its troops out of syria, the sft may have few opgs. they cannot align themselves with the turks. they re enemies, of course, and if they go with the assad regime for protection, the u.s. will cut relations with them because the u.s. cannot legally do business with assad. barbara star, cnn, baghdad. all this comes after a series of tweets from president trump that read to many like a threat. he said europe has to take back hundreds of isis fighters and put them on trial. if it doesn t, the u.s. will be forced to release them and they could then permeate europe. let s get more on all of this with cnn security analyst bob bard. he joins us from washington. bob, always great to talk with you. it s not the first time, of course, we re hearing this warning that the defeat of isis won t mean a total end to the terror group, but now a u.s.